Method of making inflated balls



Nov. 15, 1927. 1,649,734

F. T. RCBERTS ET AL METHOD OF MAKING INFLATED BALLS 3 Sheets-Sheet 1rfiw Filed Avril 16, 1925 3 Sheets-Sheet 2 F. T. ROBERTS ET AL METHOD OFMAKING INFLATED BALLS Filed Avril 16, 1925 Nov. 15, 1927.

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' F. T. ROBERTS ET AL usmon OF MAKING INFLATED BALLS Filed April 16,1925 3 Shets-Sheet 3 Patented Nov. 15, 1927.

UNITED-STATES PATENT OFFICE.

FRED THOMAS ROBERTS, 0F UPP R MoNToLAIR, AND WILLIAM EUGENE ROBERTS, 0FLITTLE FALLS, NEW JERSEY, ASSIGNORS To PARAMOUNT RUBBER CONSOLIDATED1110., 01' LITTLE EALLs, NEW JERSEY, A CORPORATION 0E DELAWARE.

METHOD OF MAKING INFLATED BALLS.

Application filed April 16, 1923. Serial No. 632,227.

The purpose of this invention is to make a durable and satisfactoryfootball, soccer ball, or similar ball of rubber, and which shall havethe appearance of the usual leather casing of such articles and whichmaybe cheaply and economically manufactured by a simple and eflicientprocess. Hollow rubber articles containing internal pressure can be madein almost any conceivable shape by various processes, but to supply thedemand for rubber footballs, it is necessary that they shall have theappearance, weight, balance, resiliency and a surface as nearly similarto the usual footballs as practicable. It is desirable in making therubber surface to have the appearance of leather, that shall be slightlyrougher than as though it were a true imitation of leather, in orderthat it may be firmly gripped and slipping of the fingers when catching,throwing or passing the ball, may be avoided.

In the making of molds in which the article is finished a treatment ofthe surface of the mold to produce the appearance of a r leather casing,would be very diificult or at least very expensive bythe use of anypreviously known methods of making such molds. Another object of ourinvention therefore, is the accomplishment of a simple expedient inmaking the molds, whereby we may secure the above results, in makingpernanent molds in which the rubber may be formed.

Another specific object is the provision of simple means of inflationwith the proper desired pressure. drawings, we have shown a method formaking the molds, and showing the resulting article, the followingdescription havingreference to the drawings. is intended to make clearthe method of carrying out our invention.

An advantage of our process and the unique desirable results obtainedare set out in the following description.

In the drawings, Fig. 1 is a section through a pair of the forming moldsin a press showing the manner of seating sheets of rubber stock in thecavities, the stock being here illustrated as seated and about to beunited and severed along the meeting edges of the molds; Figs. 2, 3 and4 are sectional details showing the mold and rubber lining adjacent thevalve and illustrating the steps of In the accompanying securing thevalve and vulcanizing it in the article; F g. 5 is a plan viewof one ofthe molds; Fig. 6 is a transverse central section through the patternplaced in the sand for casting the mold; Fig. 7 shows the mold beingcast in the sand; Fig. 8 is a diagrammatic view in the nature of anenlarged sect onal detail illustrating the relative position of theleather on the pattern; Fig. 9 is a similar view illustrating the sandafter removal of the pattern; Fig. 10 is asimilar view illustrating thesurface formed on the mold cast in such sand; Fig. 11 is a similar viewshowing the contour of the surface of the rubber formed in the mold;Fig. 12 is a view of a suitable vulcanizing mold partly in section; Fig.13 is an enlarged sectional detail showing valve mechanism and atemporary plug for use-in positioning the biscuit in the vulcanizingmold. Fig. 14 is a View of the completed footballinfiated.

Fig. 14 illustrates one form of football made in accordance with thepresent invent1on, comprising a single thickness of tough, yetresilient, rubber, the wall being divided into gores by grooves formedin the outer surface. giving the appearance similar to the usualfootball, these grooves being desig nated 5 and 6, while at the junctureof two of the apparent gores, the ball is given the appearance of thelacing opening by grooves 7 looped to define the space 8 usuallyoccupied by leather inserts, there being depressions 9 to indicate theusual openings through which the lacing extends. The lacing isrepresented by ribs of rubber 10 connecting these openings as shown. Asomewhat larger groove 11 represents the space between the two apparentinserts 8, while integral with the wall of rubber is a tubular portion12 forming a valve opening.

For convenience in illustration, the surface in Fig. 14 is simplyindicated as roughened or irregular, while the enlarged view of Fig. 11is intended to show more clearly the actual appearance of the surfaceupon the wall portion B of the ball. This surface in general appears tobe a finish of leather but the fine grooves and hair depressions of thenatural leather are reprehowever, that, if desired, an actual truereproduction of leather may be made, as is set out hereinafter inconnection with the steps of the present process.

I We form the article from sheet rubber by pneumatically seating it inmold cavities which are then brought together to join the portions in anedge seam and to cut off the shape of one half of the article. orpreferably having an inward hump 42 as set out in Reissue Patent No.14,604. These molds have chambers 43 in their bases which communicate bpassageways 44 with the mold cavities. uitable suction pipes 45communicating with the chambers enable the air to be exhausted from thecavities to pneumatically seat therein sheet rubber stock A. The moldsmay be secured against platens 60 and 61 of a suitable press. Around theoutside of the mold cavities 41 we have shown grooves 46 from whichsmall passages 47 lead to the vacuum chambers of the molds. so thatsheets of rubber stock A laid across the molds upon an application ofthe vacuum are securely held around the outside of the cavities, whilevacuum beneath the sheets may draw them into the molds. as shown.

Around the mold cavities are provided the raised cutting edges 48serving to unite the edges of the stock within the cavities, and severit from the surrounding sheet after the manner of the process describedin the prior patents mentioned.

As a suitable means for forming a valve, we have chosen a constructionillustrated in Fig. 13 where on the inside of the wall B. opposite thetubular projection 12 is an inwardly projecting body of rubber 20 inwhich is imbedded a thin. threaded ferrule 21, preferably having aflange as indicated at 22, imbedded in the rubber and having an innerend wall provided with an opening 23 registering with an opening in therubber 20. lVithin the ferrule is a rubber gasket 24 against which maybe seated a hollow plug 25 having an opening 26 closed from the interiorof the football by the gasket 24 when in the position shown in Fig. 13.As the plug 25 is screwed outwardly slightly, it will be seen that airmay pass through the opening 26 through the gasket 24 and opening 23. Athreaded washer 32 embracing a t'errule 21 facilitates the placement ofthis ferrule and assures it being firmly secured in the rubber 20.

To position and secure the valve mechanism described, we may cause thesheet stock of one mold when seated to be pressed over an upwardlyprojecting threaded pin 70, having a suitable screw head 71 with whichll; may be removed. and having its upper end beveled at 72 to cause itto pierce the rubber more easily. Around the pin is a cavity 15 formingthe tubular projection 12 around the valve opening of the article. Vhenthestock is first seated, it takes the position shown in Fig. 2 and wethen press the ferrule 21 over the pin forcing the rubber inlo he cavity15. .1 pellet of rubber 20 is placed around this ferrule and over theflange and pressed into contact with the previously seated stock asshown in F ig. 3, and the washer 32 may be then threaded on the ferrule.and another aellet of rubber 20 placed over this washer and all of thesepressed downwardly into the position shown in Fig. 4. \Vhen the articleis removed from the mold. it will be seen that these parts will slideeasily off from the pin and when in the vulcanizing mold, they willhomogeneously unite embedding the valve parts firmly as described. Asmall hole 23 may be cut through the upper portion of the last pellet ofrubber 20".

The vulcanizing mold illustrated in Fig. 12 is formed in a peculiarmanner as hereinafter explained in detail for the purpose or giving theball the leatherlike appearance desired. The mold members are heldtogether by any suitabl means as for example the grooved wedge members82 which engage tapered ribs 83 on molds. As shown in this view. thisvulcanizing mold comprises two members 50 each having a hemisphericalcavity and one of the members has at the bottom of the cavity a smallopening 30 in which is placed a plug 81 which screws :nto the valveferrule as shown in Fig. 13. This properly positions the article andcauses the ribs and grooves in the mold which form the ribs, the pad andthe lacing heretofore described. to come in the proper place.

Convenient means for inflating through such a valve as described is touse a tapered nipple connected with an air hose and adapted to wedgetightly into the inner surface of the plug 25. whereby the plug may beturned. After inflation to the proper pressure. rotation of the nippleand plug sets the plug against the gasket 24 and seals the opening.

is shown in Fig. 12. the general shape of the vulcanizing mold is thatof a reclangular cast metal body 50 having a cavity 62 corresponding toone half of the foot all a molded. while opposite the cavity the metalprojections and ribs corresponding to the configurations of therepresentation of lacmg and ommg of the gores. This pattern isdesignated Fig. 6, and is shown as surrounded by the molding sand Swhich is of course carried in suitable mold boxes. This pattern is ofcourse shaped to provide for the flanges 54 and the othercharacteristics to be given the casting comprising the mold. It is shownas lined with a layer of natural leather L, with its finished or outersurface presented to the sand at the male portion of the sand mold. Thisleather is selected to produce the characteristics of a football, forexample, a good grade of pigskin, such as is frequently used on highgrade footballs. The pattern is then reing the rubber-working moved fromthe sand and the metal formmold 50 poured into it as shown in Fig. 7 andthis casting forming the mold member is then suitably finished andmachined, where necessary.

Referring to Figs. 8 and 11, we may consider Fig. 8 as a section througha portion of the vulcanizing mold pattern, in which the wood or othermaterial forming the body of the pattern is designated 50*, while Lindicates the surface of the leather and it will be noted that thelarger convexities face outwardly. Now when the sand S is formedcomplementary thereto, the larger convexities project inwardly as shownand the small pointed depressions form outwardly projecting points onthe sand as at L The metal mold surface 50 cast against this sandsurface is illustrated in Fig. 10 where it will be noted that thesurface of Fig. 8 is reproduced, the projections and indicated at 5O and50 After the rubber article is formed in the forming mold, the propershape and size, it is transferred to the vulcanizing mold 50, and herevulcanized with sufiicient internal pressure to cause the rubber toconform to the surface 50 and to form the grooves defininglthe gores andlacing opening representations. The representation of the leathersurface reversed, is indicated diagrammatically in Fig. 11 on thearticle itself, where we have the depressions and projectionsreproduced. The pointed projections are indicated at 16 at either sideof the curving depressions. Projections, see

Fig. 5, 5, 6* and 7 and depressions 10 and 12 in the mold correspond tothe depressions 5, 6, etc., and raised portions on the ball.

It will be seen that the reproductions of such a finish on a surface ismade up of depressions and projections having a certain relationship tothe concavo-convex surface depressions being.

of the mold and article and that through the successive steps therelationship of these projections remains the same, but the effectisreversed through the successive steps. That is to say, the leathereffect is natural on the concave surface of the pattern and resultingmold, while it is reversed on the convex surface of the sand and thefinished article.

From the foregoing description, it will be seen' that we have provided asimple and effective method for the manufacture of afootball of rubber.The selection of the material for rubber is such that it is resilientand yet tough, capable of standing abuse when in use, while the finishedarticle has the very close resemblance to a leather foot ball, providedwith the usual rubber bladder. Coloring the rubber substantially that oftan pigskin gives an accurate and pleasing imitation of a football.

l/Vhile the imitation leather effect on the surface of the rubber asshown is more desirable in the sense that it provides a slightly roughersurface on the exterior avoiding likelihood of the hands slipping, wemay make the exact imitation of leather, forming the preliminarypattern, of a material, say such as plaster of Paris, the leatherimitation being placed in the inner surface by leather over the outsideof a male member, corresponding to one half of the article, Theprojections and depressions of the leather will then have the samerelationship to the general curve of the convex surface of the finishedarticle, as on a leather football itself, with the result that throughthe successive steps described, the consequent reversal of theprojections and depressions will be just the opposite asthat describedin Figs. 8 and 11, and a perfectly trueimitation of the leather will becaused to be effected on the surface of the finished article. It is tobe understood that both of these methods are intended to be includedwithin the present invention.

Notice is given that the football herein sheets for a valve opening,positioning the valve parts and surrounding them with rubber built up onthe interior of the sheet, thereafter closing the article and unitingthe sheets to complete the article, and-finishing it in a vulcanizingmold with" internal pressure.

2. The method of making footballs and similar articles, comprisingpneumatically.

seating rubber sheet stock in mold cavities. one of which is providedwith a pegto perforate the stock in a certain region, and thereafterpositioning a valve ferrule by means of such peg on the interior of theseated stock, then bringing the two ortions of seating stock intoconjunction to orm the biscuit, then transferring the biscuit to thevulcanizing mold, then vulcanizing it with the valve ferrule in place.

3. The method of making footballs and similar articles consisting ofdrawing sheet rubber stock in mold cavities by suction, one of the moldmembers being provided with a pointed peg projecting toward the interiorof the cavity, mounting a valve ferrule on the projecting portion ofsaid peg on the interior of the seated stock, thereafter causing theseated stock to be joined and finally vulcanizing the article with thevalve ferrule in place.

4. The method of making hollow rubber articles having valves, comprisingplacing sheet stock across the mouths of mold cavities, exhausting theair from such cavities to seat said stock by suction, one of the moldmembers being provided with a peg projecting into its cavity, wherebythe said stock may be perforated about the peg, then placing a valveferrule on the internally projecting portion of the peg, then applying arubber reinforce about the valve ferrule, then joining the two parts ofthe article, then transferring the formed biscuits to a vulcanizing moldand vulcanizing it.

5. The method of making footballs and similar articles, comprisingplacing raw peg, applying rubber about the valve ferrule and over itsflange, screwing a nut on the ferrule. applying rubber over the nut,whereby the ferrule and nut are embedded in rubber. then joinin parts ofthe article to form a corn lete c osure with heat expanding materialwithin it, and finally transferring the article to a vulcanizing moldand vulcanizing it by heat with internal pressure.

5. The method of making valved rubber articles. comprising seating partsof the article pneumatically in mold cavities, one of the mold membersbeing provided with an inwardly projecting peg, mounting a valve ferruleon such peg, reinforcing the ferrule on the inner side of the article,bringing the article parts together to join them, removing the formedbiscuit from the mold, positioning a peg from the eiterior in the valveferrule, and placing the biscuit in a vul- 'canizing mold which has arecess to receive the peg, and surface indentations and projections tomold the exterior surface of the article in representation of a lacedleather football.

in testimony whereof, we hereunto aifix 111 signatures.

FRED THOMAS ROBERTS. WILLIAM EUGENE ROBERTS.

